The invention relates to a card index for fixing to a vertical wall or for placing on a base, comprising a basing for receiving index cards with selection tongues forming a staircase-like arrangement running from one side of the card to the other and carrying prefixes, letters, reference details, etc and means for holding and releasing the index cards selected by means of a set key.
Card indexes with selection devices are known in many different forms. They comprise a casing for receiving a stack of loose index cards and a keyboard with correspondingly marked keys, whose operation leads to the selection of the desired cards. The index cards can carry in alphabetical order random details or notes for subsequent reference. A known construction of a card index is relatively flat in the closed state and is opened by means of a plurality of keys operated manually in order to open the index at the desired point and to make the information on the cards freely visible. In addition, an index constructed in this way is provided with a closing key by means of which the cover covering the index cards can be brought into the closed position. Simultaneously with the closing of the cover, the raised cards are automatically returned to the initial position.
In addition, a card index is known comprising a casing with a drawer for receiving the index cards under the action of a thrust spring and closed by a bolt and with a device for unlocking the drawer and releasing the card selected by means of a set key by forcing out the unlocked drawer by means of the thrust spring.
These known card indexes are constructed in console form and are placed on a base support. The card index casing can also be provided with a base for supporting a telephone, if said casing is provided with a drawer moving the selected cards out of the casing.
In the case of these known card indexes, incorrect manipulations often occur, due to the high frictional forces down between the individual cards which particularly occur when the cards have been in use for a long time. Due to the said frictional forces, not only the selected card, but also further cards are often moved out together with the drawer, because the holding-back devices provided in the card index do not have an adequate locking and holding-back action for the index cards located above the selected card and which are not to be moved out with it.